This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 115d. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
2024-10-26
[Voted into WP at April 2005 meeting.]
Can a using-declaration be used to import a namespace?
namespace my_namespace{ namespace my_namespace2 { int function_of_my_name_space(){ return 2;} } } int main (){ using ::my_namespace::my_namespace2; return my_namespace2::function_of_my_name_space(); }
Several popular compilers give an error on this, but there doesn't seem to be anything in 9.9 [namespace.udecl] that prohibits it. It should be noted that the user can get the same effect by using a namespace alias:
namespace my_namespace2 = ::my_namespace::my_namespace2;
Notes from the March 2004 meeting:
We agree that it should be an error.
Proposed resolution (October, 2004):
Add the following as a new paragraph after 9.9 [namespace.udecl] paragraph 5:
A using-declaration shall not name a namespace;